Air-cooled condenser



1,636,521 July 1927' F. LJUNGSTROM ET A AIR COOLED CONDENSER I Filed April 1.3; 1922 2 Sheets-Sheetl Fly? 1 MQJQWJ'S E 1/ zu y-sijr zi I. 0.1

I r if 1,636,521 July 1927 F. LJUNGSTRGM ET AIR COOLED CONDENSER 2 Sheets-Shut 2 Filed April 13. 1922 mamas J12; wzzysizam 1.122 obezz 1 Patented July 19, 1927;

UNITED STATES PATENT OFFICE.

FREDRIK LJUNes'rnoM, or

LIDINGO-BREVIK, AND ISIDOR BROBERG, OF SIKAIlEtSA'IlRA,

SWEDEN, ASSIGNORS TO AKTIEBOLAGET LJUNGSTBDMS ANGTURBIN, OF STOCK- HOLM, SWEDEN, A CORPORATION.

AIR-COOLED CONDENSER.

Application filed April 13, 1922, Serial No.

i let pipe has served as a supply pipe for another group of cooling elements, whereby the whole air-cooled condenser is divided into two or more groups connected in series. In each of such groups the steam supply is common for all cooling elements, independ ent of thecooling capacity of each cooling element. If such a condenser is plaoed in the open air and the external temperature is low, cases may occur when, for example,

a greater cooling capacity is imparted to one cooling element than to the others by the air surrounding the condenser. In such cases the steam entering the said cooling element is condensed quicker than in the other elements, without the condensed steam being replaced by a sufiicient amount of fresh steam, by reason of which the element will for a great part contain moist air, the moisture of which will freeze to ice in case the temperature is below zero and may entirely stop up the passage of the cooling element, thereby incapacitating the element with the danger of its freezing and bursting.

The present invention relates to an aircooled condenser comprising groups of cooling elements, the said elements being placed side by side and connected-to manifolds, each of which serves as the outlet of one group and the inlet of the next group, the outlet end of each element being throttled to a smaller crosssection than its inlet end. With this arrangement the fall of pressure between the outlet end of the element and the manifold into which it discharges is so great that an outflow from the element is always obtained, even when the cooling effect is not uniform.

In the accompanying drawing which illustrates the invention Fig. I shows diagrammatically an embodiment of a condenser according to the invention and Fig. II shows a diagram of the falls of pressure 552,410, and in Sweden November 8, 1921.

in the same. Figs. III, IV, V and VI illustrate different details.

Fig. I shows a condenser in which the elements 11 are divided into groups 1, 2, 3, connected in series, so that the steam passing group 3 has already passed through group 1 and then through group '2. 4; denotes the inlet pipe of the whole condenser and 5 the outlet pipe thereof leading to an air pump. Pipe 6 is the outlet pipe or manifold ofgroup 1 and the inlet pipe of group 2, while pipe 7 is the outlet pipe of group 2 and the inlet pipe of group 3. From the manifolds 6, 7 and 5, the condensate water is drawn oil through the pipes 8, 9 and 10. In a corn denser without the above-mentioned sub-division in groups, the manifold 6 is connected directly to the air-pump, groups '2 and 3 being omitted.

The diagram disclosed in Fig. II shows the falls of pressure in the condenser shown in Fig. I, the ordinates representing the pres' sure and the abscissas the distances of the points in question from the supply pipe 4. Supposing a pressure of P prevails in sai pipe 4 corresponding to the point 12 in the diagram, then in a condenser of the type heretofore known the fall of pressure'P des-, ignated for the whole condenser is divided for instance into a fall of pressure P in the first group, a fall of pressure P in'the second group and a fallof' pressure P, in the third group, the pressure of the different groups falling according to the curves 21, 23 and 2& respectively.

If now for some reason or other the tube group 11 has exercised an increased activity for some time, then all. the steam may be condensed for instance at 11 On account of this condensation nearly the whole fall of pressure P intended for said group has occurred, and the pressure in the remaining part of the group will hardly surpass the pressure of the pipe 6. The remaining fall of pressure P is not sufiicient to exhaust the moist air from the element, and consequently said air will remain in this part of the element where the formation of ice may cause bursting of the element.

In the embodiment of the present inven tion as shown in Fig. I the outlet of each cooling element is markedly reduced. This result is obtained by arranging a throttling disk 11 at the outlet end. Hereby the pre;- manner, thus producing a passage area which sure conditions in the condenser will be altered. The fall of pressure P, for the whole condenser, will be divided into P for the elements of the first group, P torthe ele ments of the second group and P for the elements of the third group. In the elements of the first group the pressure falls according to the curve 22 to the point 15 immediately beforethethrottling disks 11 and then a markediall of pressure will occur, the line 1.6 representing the fall to the pressure of the pipe 6. In the elementsotthe second and thirdgroups which are also provided with throttling disks ,the falls of prssure will follow the curves 26 and 27 respectively, abrupt fallsot pressure arising at the outlet openings. The fall of pressure P available' for the whole condenser is not surpassed in the embodiment ehewn, by reason of the fact that the elements of a following group 2 and 3 havegreater passage areas than thoseot a preceding group 1 and 2, thuscausing a decrease of the resistancein same so that c' onsequently the'steam requires a smaller tall oil pressure i'or passing through same.

lithe elements of the second group are not provided with any throttling disks, hut have greater passage areas thanlthose of the hrst group, the pressure will fall according to the curve 25, the tall ot pressure P at disposal for the first two groups being not sur-- passed.

It is evident that should the condenser consist of only one group of elements, the increased fall of pressure iiecessary on account of the throttling of the elements may be obtained in any manner, as for instance by in troducing the steam in the elements" at a higher pressure than before or; by maintaining a lower vacuum in the condenser. These measures may also be taken in case of the condenser consisting of several groups connected in series, the increase of the crosssection of the elements of a following group in relation to a preceding group may then be dispensed with. I

In order to obtain a throttling action of the elements, throttling disksmay be used, as mentioned above, at the outlet of the element. Instead thereof thecross-section of the elements from the inlet end to the outlet end may also be continually decreased, which in certain cases may be more advantageous than the use of throttling disks partly from a manufacturing point of View and partly from consideration of space. If the elements consist in known manner of flattened pipes, the height h at the inlet side A ofsuch a pipe may thus be reduced along the whole length of the pipe to a height h at the outletend B, the outlet area at Bgbeing then also smaller than the inlet area at A. According to Fig. IV, the thickness 5 of the element may be continually decreased in the same plurality or group's'of cooling elements, th

is contractive toward the endof the outlet.

It in known manner several elements 31 are inserted in a common collecting pipe 32, as indicated in Fig. V, throttling may be obtained for the whole of this combination of cooling elements inthe collecting pipe 32 by the insertion of a throttling disk 36 into the lower narrower extension 01 the collecting pipe 32, or by the reduction of this pipe, as shownat 37.

Then it may also happen that a cooling element in this combination, compared with the other cooling elements in the same combination, may produce a greater'cooling effect the said cooling element having then, preferably, to be throttled independently otthe' remaining cooling elements. This ispreierably attained by th element being, flattened so. that the element changes its cross-see tional appearance from the tulllines to the daslnlin'es, as shown in Fig. VI at Fur 7 thermore,a whole disk with narrow openings 7 or small apertures may be placed in fronto'f the mouths, as shown at 34. i o

Vhen, as shown in Fig. V, several elements in eachgroupare inserted inacfommon collecting pipe, such an arrangement may also be'appliedto Fig. I, as in this case the elements 11 shown in this figurejrepresent each such an under group, comprising for instance 'lo'ur or five elements 31 and the corresponding collecting pipe 32. v

' Having how particularly described and as certained the nature of thesaid invention and in What manner the same is to' be performed, ive declare that whatWe claim is:

1. An air cooled condenser comprising gi 'oup s ofcooling elements, the elements of each group being placed side by side, said groups being connectedin series, and throttling means between one group and the fol: lowing. i i

2. An 'air cooled condenser, comprising a elements ofeach group being placed side by side and having inlets and reduced outlets, said groups being connected in seriesl 3, An air cooled condenser, comprising a plurality of groups of cooling elements,th e elements of each group being placed side side, said groups being connected in series, each element of a following series havinga larger passage area than each element of a previous series. v y

4. An air cooled condenser, comprising a plurality of cooling elements, the elements of each group being placed side by side and having inlets and reduced outlets, said groups being connected in series each element of a following group having a larger passage area than each element of a previous series.

5. An air cooled condenser, comprising a plurality of groups of cooling elements, the elements of each group being placed side by ltlti llU side and divided into several under-groups each comprising a number of cooling elements, said under-groups being connected in parallel Whereas said groups are connected in series, and throttling means between one group and the following.

6. An air cooled condenser, comprising a plurality of groups of cooling elements, the elements of each group being placed side by side and divided into several under-groups, each comprising a number of cooling elements, a collecting pipe common to all elements of each under-group, said groups beingconnected in series, Whereas the undergroups of each group are connected in parallel, and athrottling member in the outlet of each collecting pipe.

In testimony whereof We aflix our signatures.

FREDRIK LJUNesTRoM. rsrnon BROBERG. 

